I (22M) don't know what to do with my situationship (26F)

I'm not sure if this is the right place for this but I need help on my situationship, which was basically a relationship with actually calling each other boyfriend and girlfriend

Me (22M) and my situation ship (26F) have been going on for about 4 months, when we started she already had the plan to move away for about a year, so we knew that it would have to end. Prior to us becoming a situationship we were good friends and I knew all about her ex which they split up due to him going travelling. she has now left and I can't stop thinking about her no matter what. While she is out there she has met up with her ex, and she has stated to me that nothing is going other than happen between them. I fully believe her and even if they did do something, it's none of my business, yet I feel so unbelievably jealous like I've never felt before. We have discussed me and one of our other friends going to visit her the start of next year and I'm so so nervous that when I do things will be different. We also spoke about when she moves back and what will happen between us because she wants to try and settle down, not with me in particular just in general. But I don't know if I should even bring it up to her because i dont know if that is what I was as 2 months before the situationship began I ended a almost 4 year realtionship and I'm not sure if that's what I want.

the main point she made to me about us becoming a relationship is the age difference, that due to her being older she's ready for more than I would be as I'm younger and have recently got out of a realtionship,

I don't know what to do, do I mention how I feel to her? Do I suggest us trying the full relationship? do I just wait and see what happens?